Although most computer components have become significantly faster as technology has advanced, personal computer displays still take a long time to “light up” for usage. This is true even though LCD-based monitors, which have become highly popular, are usually considerably faster to light up than CRT displays. For example, when returning from a reduced-power (e.g., deep sleep) mode, LCD displays typically take from two-and-a-half to six seconds from the time that they receive a valid video signal to when they turn on the backlight. One undesirable result of this lag is that the user has to wait for the display, and often winds up staring at a blank screen, even though the rest of the computer system is ready to be used.
Although there are various design concepts that display vendors may implement to reduce current “light-up” times, none of them are likely to substantially eliminate the user's waiting time. For example, with displays having many inputs that support a wide variety of video signals, vendors will likely be unable to get the light-up time to below two seconds, which is still a rather undesirable wait time. Leaving the host controller and display controller chipsets running might help speed up the restoration time, (e.g., leaving the host graphic chipset powered up ensures that the display is receiving active synchronization pulses so that the display is aware of its current mode), but is not a viable solution, as this consumes too much power to meet desired energy consumption requirements. In general, this is because leaving the host graphic chipset enabled prevents the majority of the display controller being powered down to save energy, and power savings typically comes from being able to power down significant portions of the host controller and the display controller.